Try this to find the usage hours:
Hidden Secret Service Menu Codes for Sony, Samsung, LG and Philips TV
Service Menu Code For LG TV:
Press and hold buttons on remote as well as TV panel for a few seconds and the service menu will appear on your TV screen.
"LG_TV_Remote_Service_Code.png"
For some TV models, you might need to press "Menu" buttons on remote and TV panel simultaneously for a few seconds to access the service menu. In a few TV models, both methods work and they open different service menus.
If the service menu asks for a password, enter 0000 (four zero). If 0000 doesn't work for you, try 7777 or 0413 or 8741 or 8743 or 8878.
Now you can make changes to your desired settings.
To save the changes press button on the remote.
BONUS TIPS:
1. With the help of this secret service menu in LG TV, you can enable USB drive use by settings USB option to 1. Once you enable this feature, you can insert any USB drive in USB slot present at the backside of your LG TV and your TV will automatically detect it and you'll be able to play audio or video files present in your USB drive on your TV set. You can also view images present in your USB drive on your TV set.
2. You can also enable Golden Eye feature by settings Eye option to 1 in service menu. This feature automatically adjusts contrast and brightness levels of your TV set according to the lights available in your room.
3. All LG TV come with a secret feature called "Hotel Mode". You can enable this feature by settings Hotel option to 1 using service menu. Once you enable this feature, the Setup or Channel Search option will get disabled in your TV Settings. Thus no other person will be able to scan channels or fine tune channels. That's why this option is called Hotel Mode.